Manufacture of storage battery units



J1me 1931- F. w. BARHOFF I MANUFACTURE OF STORAGE BATTERY UNITS F iled Dec.

Ana/v70? Patented June 23, 1931 UNITED STATES FRED W. BARHOFF, OF HARTFORD, ,CONNECTICUT, ASSIGNOR TO ENGINEERING PROD- 'UCTS CORPORATION, .OF HARTFORD, CONNECTICUT, A CORPORATION" OF- DELAWARE MANUFACTURE OF STORAGE BATTERY UNITS Application filed December 22, 1928. Serial No. 827,932.

In the art of welding metal to a homogeneous state, it is -well known that if molten metal be deposited on or in contact with a plate, block, or other mass of similar meta-l in non-molten condition, unless the latter be raised to a temperature approaching a molten state, deposited molten metal willnot e e t a weld, because the chilling surface of the s eet or other mass of non-molten metal causes solidification of the static molten metal at the places of contact incident to the heat absorption 'by the sheet or other mass of nonmolten metal from the molten metal, and

. distribution of heat frommore remote p01- tions of the molten metalthan the contacting portions is not-suificiently effective to penetrate solidified parts of the formerly molten s-meta-l and to raise the temperature of the contacted parts of the sheet or other mass of non-molten metal tothe requisite condition for entering a homogeneous state or perfect 7 weld with the molten metal. To obtain a perfect weld and avoid heat and other losses,

the present"invention provides for. increasing the time of exposure of the non-molten mass to thedir'ect action of the molten metal, for-a period prolonged beyond the action ob-- tained when solidification of'the molten mass is permitted upon contact with the nonv molten metal, or when the molten metal is flowed freelyacross the non-molten metal.

- A specific application is found in the constructing-of the lead parts of'a secondary v cell, commonly referred to as a 'storagebattery. It is common practice to construct the positive and negative plates with upstanding tabs, which are commonly referred to as lugs, and when the platesare assembled in the relation arranged in a cell, a strap is fused to the several lugs of all of the positive plates -ahd likewise a similarstrap is welded to the several lugs of the negative plates, and each strap is formed with an upstanding post to receive the respective lead connector. Prior to the presentinvention, "it has been common to cast the 0st and strap as a unit,.and then burn t e strap to the upstanding plate lu s. The fusing or burning is accomplished y the use of a torch requiring the services of a skilled operator. Attempts have been madeto cast the post and strap in contact with the plate lugs andto cause the heat of the molten metal during the cast to form a union with the lugs, but prior to the present invention such attempts have not been successful for the reason indicatedabove, and particularly because the temperature of the plate lugs is not raised to the requisite degree for producing a weld,

prolongation of contact of molten metal with non-molten metal action stated.

Another object of the invention is the effective anchorage of the strap and post to the for effecting the welding respectivegroup of battery plates while the plates are assembled inthat relation assumed 1n 2. battery whereby all the parts to complete a cell may be assembled with the exceptlon of the posts and straps andthe latter cast with the parts so assembled.

A still furthur object of the invention is the relative location of the parts ,such that gravityis taken advantage of in the ezipo'sing of the non-molten metal part to the maximum heat ofthe molten metal being cast.

Further, and'inore generally speaking, the

objects of the present inventon include the provision of a method of and apparatus for uniting the plate lugs and straps of storage batteries in a manner enablin the doin away with the implements an appliances commonly employed for burning straps to battery plate lugs and the elimination of the dangers and injurious eflect's of workmen incident thereto as well as to effect the saw-- ing in labor, time, and equipment'incident to such burning, whereby battery units may be produced more quickly, cheaper, and more satisfactory than previously.

With these andnumerous other more detailed objects in view, as will in part hereinafter become apparent and in part be,

stated, the invention comprises the art of welding by the utilization of the temperature of molten metal as the sole temperature raising agent.

The invention also comprisesin greater detail the rendering of metal parts homogeneous at a lace of contact incident to prolongation 0 contact of flowing molten metal .with a non-molten metal part.

In still greater detail," the invention comprises uniting the lead parts of a storage battery by the casting of one of such parts in contact" with a previously formed part under conditions delivering sulficient heat from the part being cast to raise the temperature of the'previously formed part to a molten state or a state sufficiently approximating a molten condition to cause the previously formed part and the part being cast to blend to a condition of homogeneity.

The invention also comprises certain other novel steps and combinations of steps and certain novel constructions, combinations, and arrangements of parts as will hereinafter become apparent.

While a will be obvious that the invention is capable ofbeing carried out by the utilization of any of'numerous forms of apparatus and numerous arrangements of parts, a specific application of the invention can be best disclosed by reference to a particular, preferred mode of procedure and arrangement of parts. To this end, while not limiting the invention to the specific illustration now to be stated, the objects above expressed with other objects which will become apparent may be attained by the employment of a matrix formed of separable parts and held together during the operation and provided internally with the required recess and passagefor the casting of a' strap and post with the-postspaced at one side of the line of the row of plate plugs to be united. The battery plates are assembled in that relation which they will assume in the finished battery, and when and if desired, separators may be inserted therebetween, and the two setsjof plates, positive and negative, may also be interlaced so that a complete cell unitis assembled, however metal flowing into positon to form the post strap. When the parts are thus assembled, the molten metal is poured into the matrix at that side remote from the recess for the formation of the post, so that all of the metal to form the post and strap must flow past and in contact with the tips of the plate lugs, and, under some conditions, as will be hereinafter specified, a flowin excess of that represented by the bulk of metal eventually incorporated in the post and strap may be utilized. Furthermore,the metal flowing past the row of tips of plate lugs is preferably retarded in its progress by providing in the matrix an obstruction or part restricting the cross sec tional area of the flow of molten metal'at the place of contact with the lug tips. This restriction may be accomplished by the provision in the matrix of a riflle or dam across which the molten metal must flow and due to which the molten metal may not flow as rapidly and with the same cross sectional area as I it would if the passage were unobstructed. I

will be formed and the strap will be found to be integral with the plate lug tips.

It. has been found by experiment and satisfactory tests that the results just stated may 1 be obtained more readily'and more satisfac torily by inverting the battery unit, so that the lug tips project downward into the mold or matrix and the riflle lies across the path of the flowing metal at the bottom of the passageway provided for the strap, so that the flowing metal must rise over the rifile and flow past thelug tips contact with the lower portions of the lug as considered in their inverted position.

In the accompany drawings,

Figure 1 is a view in front elevation of a mold .and battery unit assembled in position for practicing the present invention, the shaft of the mold separating screw being seen in section and the operating hand wheel accordingly omitted.

Figure 2is a side elevation of the same including the hand wheel.

Figure 3 is a plan view thereof with the battery unit omitted and a portion of the central part of the mold being broken a way and parts seen in section. k

Figure 4 isra vertical, central section through the parts seen in Figure 1, the batteliy unit being seen in elevation.

igure 5 is a similar section taken on a 6 battery plates shown fr lugs united as the comp eted p plane at right angles to the plane of the section in F1 4.

Figure6 is a detailed, detached perspective view of the completed post and strap with the entaril and their uct of the practicing of the invention.

Figure .7 is a view similar to Figure 4 of a fragment of a slightly modified embodiment of mold.

The present invention, of course, is susceptlble'of expression 1n numerous ways and is applicable to various metals, but is more particularly efiicacious when a plied to semisoft or soft metals, the latter including lead g and its alloys.

To facilitate a specific illustration ofthe carrying out of one embodiment of the invention, reference will be had to the structure illustrated in detail in the accompanylease the cast ing drawings in which 1 is the bed 'ofthe matrix, WhlCh is movably surmounted by the separable sections of a. mold or matrix '2 constructed to be moved toward and from each other from a closed condition in contact to an open condition sufiiciently spaced to re arts. The bed 1 has lates 3 at its sides t at enter slots in the si es of the mold sections 2 for guiding and retainhalf, 0

shaped to form connecting straps 7. 'Each ing the moldsections on the bed. Each mold section 2 has one-half of two recesses 4 that,

are sha ed to form terminal posts 5, and onet the recesses or channels 6 that are channel 6 has its available cross sectional."

area diminished at one place by across bar or riflle 6 adapted to function as a dam, re- ,quiring flowing metal assing along the res tive channel 6'to rise about the pendent centers of t p ate lugs hereinafter mentioned into contact therewith in a thinner stream than would occur if the channel 6 were left unobstructed.

This gives a longer direct exposure'to molten metal. The mold is divided so as to be separable ion a lanexwhich passesthrough the l ese recesses 4 and 6. A spindle 8 extends through the mold from. front to back and has a nght thread 9 in one section the mold, are gates 14. These gates have mouths 15 that open at their lower ends to the outer end of the respective strap recess or channel 6 in the mold. Blocks 16 are fas tened to the front mold section and'these blocks are provided with holes 17 for receivin pins 18 that may be used for retaining moved the away from the sides of the mold.

Pivoted to the rear blocks 12 by screw studs 19, so as to be swung in a vertica plane across the mouths of the gates, are cutting blades 20. These blades, when the gates are swung out after the posts and straps have been cast, may be driven down so as to sever the excess metal from the edges of the straps. 1 1

In practicing one preferred specific a plication of the invention, the battery p ates, comprised of. grids 21 with the active material 22,- are assembled with the lugs 23 of one group alined on one side and the lugs 24 of the other group alined on the other side in the usualway and with the separators 25.

inserted between them. The plates and separators are then fastened together by a spring clip that has wings 26 which extend down the faces of the plates and wings 27 that extend down the edges of the plates. This then placed in an inverted condition between arms 28 that are fastened to and extend up from the mold sections. In this position the plate lugsextend into the strap recesses or channels 6, as illustrated in Fi ures 1, 4 and 5. With the parts in this relation, the metal for forming the posts and the straps is oured into the'mouths 15 of the gates 14. s this molten metal flows into the mouth'15, it enters gates may be swung horizontally clipped assembly of plates and separators is I the respective recess or strap channel 6 through a relative? narrow passa e between the cutting edge 0 he respective ar 20 and the spaced material of the gate 14,, which restricted opening limits the speed-of flow of the molten metal and affords a roportionally greater. opportunity for distri ution of heat from such molten metal to conti nous parts. The molten metal moves alon t e recess or channel 6 until-it strikes the mflie or dam 6,

and then backs up until it rises and overflows the riflie 6'. In overflowin the rifile 6', the molten metal is caused to delayed in its progress and also caused to move slowlglzgross and in contact with contiguous sur s of the respective plate lugs pendent into the channel 6. The flow continues until a'sufiicient quantity of the molten metal has passed beyond the inner terminal of the strap chan-Y nel 6 into the ost recess 4 to fill said recess. When this is one, suflicient molten metal is still admitted to the channel 6 to fill the chan-.

nel, and-then the supply of molten. metal to the respective mouth 15 is discontinued. The gates 14 are then swung away, the knives 20,

lowered to shear off the projecting flange of metal, and the moldasections 2 moved apart to release the newly cast parts. When this is done and the unit is removed, it will be found to be complete with the finished post 5 and strap 7 in each instance integralboth between themselves and with the'lugs of the battery plates, as clearly seen in Fi re 6. A groove 65 t egates in pmition; When the pins are re- \6" also be found to exist in the strap 7 due to the presence of the riflle 6', but said groove 6" is only an incident.

During thezcourse of the flow of molten metal along the respective channel 6, as the melting point of the metal of the plate lugs 23 and the metal from which the post and strap is formed varies but 1i'ttle,the ends of the lugs are heated to thedesired degree by the metal slowly passing the plate lugs onthe 10 way to the, post cavity and by the time the inflowing metal 'fills the recesses and reaches the lines X on Figures 4 and 5, the tips of the lugs become fused and homogeneously' unite with the metal which forms the connecting straps. By this method of procedure and by the use of this mold the plates and the separators may be assembled in final relation and the terminal posts and connecting straps quickly cast and coincidently united with the lugs of.

- the plates, so that the unit is completed by simply casting the metal into the mold. is is accomplished in a minimum oftime an at aminimum cost, and a battery unit produced which can be guaranteed as free from defective separators and loose connections.

a While the assemblage illustrated in themcompanying drawings is that of a complete 1 battery cell unit of plates and. separators, and the parts are shown in an inverted position, all of which is the preferred practice and is, therefore, specifically set forth above, it is important to observe that the invention is not limited to the number of plates united or -the relative location thereof or angular relation or disposition with respect to the arts of the matrix. Inversion of the plates is preferable for obtainingthe best results with least inconvenience',but efl'ective results may be produced with the plates otherwise located.

In Figure fied embodiment of mold. corresponding in structureand operationin every particular with that illustrated in the other figures of the drawings, exceptthat the mold sections 2 are provided with overflow recesses 4, each communic'atingby a port-4 with the respective'post forming recess., An air exhaust port 4" leads from the overflow chamber 4' through the walls of the mold section 2' to the atmosphere to permit exhaustion of air with the incoming of molten metahfQ This modified structure possesses the capacity of having a greater quantity of "molten metal poured into and passed along the strap form ing channel than required for the formation of the post and strap, and with this provided excess flow of metal it is practicable to Weld 6 the finished cast strap to the plate lu'g tips without resorting to the retardation. incident to the use of the riflie 6, but the sai$riflie 6- is preferably used as a further precaution.

. Furthermore, with the excess or overflow reto a homogeneous mass a strap being cast and plate lugs extending into the strap channel even though such lugs be of greater thickness than average. It will be understood, of,

course, that the amount of heatrequired for eflecting the desired welding will vary according to the bulk of the non-molten metal past which the molten metal must flow, and with increased bulk there must be an increase in the heat penetration to which the increased -bulk is subjected to properly affect the same,

which is obtained by an increasein the time element of exposure to the flowing molten metal. Therefore, when the overflow recess and strap. While Figure 7 illustrates only one of the post recesses as communicating with an excess or overflow recess 4, such an overfidw recess w1ll,-of course, be provided for both p'osts when requlred for either.

In each instance, the practic ng of the 1nstant inventlon lncludes fusing parts formed 7 of the same kind of metal by casting the molten metal at substantially the temperature of melting'without added or superheated intensity, and the molten metal is not of a substantially different or appreciably higher melting point from that of the non-molten part. I

The superheating of lead to cause fusing with a lead plate has been proposed, and it has also been proposed to fuse copper to cast iron by the heat of the molten iron; and it hasfurther been proposedto fuse dissimilar metals by using as the molten metal a metal hav- 7 1s lllustrated a slightly modiing a higher melting point than the nonmolten metal; but in each instance undesirable conditions or results are to be found from the expense and extreme nicety of the operation or the uncertainty of uniformity-in results. The present invention is characterized by' enabling fusing of the same metal without superheating the molten metal, and affording uniform and dependable xresults whereby a perfect electrical and mechanical connection orunion' is invariably produced.

-What is claimed is 1; The art of-uniting metalparts, compnsing flowing molten metal at substantially 'n'ormal melting temperature of such metal in the 1 course; of casting the same to form a part and directing the path of flow to cause contact of the molten metal with' a non-molten part of like metal, retarding the velocity of the 'flowing metal for prolonging maximum'heat'delivery from the molten metal to the nonmolten part until fusion occurs between the cess, it is entirely feasible to effectively weld formerly non-molten part and the molten 13 metal, and solidifying the parts in the fused condition.

2. The art of uniting metal parts, comprising flowing molten metal at substantially nor- 5 mal melting temperature of such metal in the course of casting the same to form a part and directing the path of flow to cause contact of the molten metal with a non-molten part of like metal, restricting the cross sectional area of the flowing metal at a place in its path of contact with the non-molten part for causing prolongation of maximum contact and heat delivery from the molten metal to the nonmolten part until fusion occurs between the formerly non-molten part and the molten metal,.and solidfying the parts in the fused condition.

3. In the art of assemblage of storage battery parts, locating 'a non-molten part of a battery in position for receiving a part to be added, casting the part to be added and, during the casting operation, deflecting the molten metal aside from its normal path to a fusing relation with a non-molten part, the deflecting action serving to prolong the period of heat transference from the molten metal to the non-molten part.

4. The art of assemblage of storage battery parts, comprising casting two parts of a storage'battery in properly assembled relation to a third part of a storage battery, and during said casting operation causing the ,molten metal forming one of the cast parts to flow past and in contact with the third part more slowly than the normally free flowing of the molten metal and thereby raising the tem-. 'perature of said third part for fusing with the second cast part, and continuing the flow of the molten metal until the cast of said sec- 40 0nd part is completed and fused to said third art. p 5. The method of manufacturing storage battery units, comprising assembling battery plates in properly spaced relation, supporting the assembled group with the plate lugs in the path of casting metal, and casting a terminal post and connecting strap in a homogeneous junction with said strap and impeding the flow of molten metal from its normal rate for prolonging the fusing action of the cast.

FRED W. BARHOFF. 

